This invention relates to a runner and pallet constructed therefrom for use in the storage and/or transport of goods and, more particularly, to a recyclable reinforced pallet and runner design.
For many years, various types of objects have been used to separate and support loads that are stored and transported generally in a stacked arrangement. The equipment that is primarily used for performing this stacking arrangement is a front end loader, lift truck or forklift truck which raises the individual loads so that they can be stacked one on top of the other or on a rack. To separate the loads from each other, off of the rack or off of the floor, a pallet or one or more spacers, risers or runners are positioned beneath the load so as to allow space for the insertion of the forks of the lift truck or the like for moving and positioning the loads for storage or transportation.
Generally, the load supporting pallets, runners and the like are used in large manufacturing and industrial plants, warehouses, wholesale and retail establishments and wherever merchandise, food products and other articles are to be lifted and carried from one location to another. Typically, these pallets or the like are mainly made from wood and consist of platforms having parallel runners longitudinally and/or transversely secured to their undersides by means of nails, staples, strappings or other suitable fasteners.
Such wooden pallets in the past have been found to be quite satisfactory in many regards for their intended use in the shifting, transportation and storage of materials and articles from one location to another. There are many advantages of wooden pallets. Wood is extremely strong on a weight basis, and machinable with standard cutting, ripping and other forming techniques. Furthermore, wood will not lose its strength in conditions of high heat, moisture and humidity.
Wood, however, has several major disadvantages. Increasing environmental awareness has become a significant factor in the packaging, transportation and shipping industries. Wood is difficult to readily recycle and, hence, many wood packaging or pallet components are finally disposed in landfills. Available landfill sites, however, are becoming full and are being closed. If landfill disposal is even available, significant fees for dumping such bulky materials are becoming prohibitive. As a result, many customers of manufacturers of heavy durable goods are prohibiting the use of wood pallets.
Wood pallets also are very cumbersome, are unwieldly and take up unnecessary and valuable space in conveyances, warehouses and other places of storage. As transportation costs have risen, the concept of moving wood pallets back and forth for reuse, which has always been a burden on the industry, has become economically prohibitive.
In international shipment of goods, wooden pallets present additional environmental problems because they tend to serve as hosts for germs and bugs. As a result, pallets are often quarantined or burned upon arrival in another country according to governmental regulations or general precautionary practices to avoid the spread of undesirable insects, bugs or germs. This has proven to be very costly and a significant economic drawback to wood pallets.
The Wall Street Journal recently recognized the many significant problems associated with wooden pallets in an article entitled xe2x80x9cAs Old Pallets Pile Up, Critics Hammer Them as a New EcoMenacexe2x80x9d and published Apr. 1, 1998. According to that article, there are purportedly 1.5 billion pallets in the U.S. and about 40 percent of domestic hardwood lumber goes into pallets. However, a third of U.S. landfills won""t take pallets. Purportedly, more than 1 million forest acres are chopped every year for pallets, skids or the like. Cost for the wood to make the pallets is increasing and the available supply of wood is decreasing.
Loads on a pallet are often transported within a warehouse or other facility on a conveyor or rollers. Commonly, wooden pallets splinter and jam the rollers of the conveyor and thereby damage the conveyor and interrupt the movement of the goods in the warehouse. The use of wood pallets on such conveyors has become so problematic that many facilities prohibit their use on roller conveyors and mandate that the load be transferred to another type of pallet for use on the conveyor or the conveyor not be used at all. Quite evidently, this is very inefficient and time consuming and a significant disadvantage for the continued use of wood pallets.
Wood pallets offer excellent strength and durability, but even these desirable qualitites have proven to be, at best, questionable justification for the continued use of wooden pallets.
To avoid some of these objections to the use of wood pallets, alternative pallet designs have been made from materials such as corrugated paperboard, scrapped paperboard, plastics, aluminum and other materials. While solving certain problems associated with wood pallets, use of alternative materials to date has only provided additional problems. Known corrugated paperboard pallets provide lightweight, inexpensive alternatives to conventional wooden pallets for some applications, but their strength and rigidity under static and dynamic loading is insufficient to permit wide spread general usage for all types and distribution of goods. Such pallets often have excessive deflection and lack beam strength, which causes their sagging under loads, thereby making the handling, stacking and racking of the pallets impractical and even dangerous. Commonly, loads are mounted upon spaced beams of a rack and the weight of the load is concentrated on the pallet at the beam. Many so called improved pallet designs do not offer the strength necessary to withstand buckling, crushing or compression when placed upon a rack under a load. A suitable pallet for use on a rack must provide minimal compression at the beams of the rack and zero to minimal deflection between the beams of the rack. Known paperboard pallets do not meet these compression and beam strength criteria for rackability.
Strength requirements for known paperboard pallets and runners have generally been inadequate. Moreover, when the pallet or runner approaches and exceeds the failure criteria, no warning or indication of the impending failure is typically evident. In other words, as a load is transported, moved or stored on a pallet or runner and exceeds the strength limit for the pallet or runner, occurs without a warning or opportunity to replace the various components.
Additionally, known paperboard pallet designs typically become compressed, crushed, milled off or damaged when used under a load being transported on a roller conveyor. Moreover, corrugated paperboard, for instance, may lose up to 50 percent of its stacking strength during conditions of high humidity and moisture when the paperboard absorbs atmospheric moisture and the like.
As loads are transported on the tines of a forklift or lift truck, the ability to insert the tines under the load from any direction is a significant convenience for the forklift operator. A so called four-way entry to the pallet by the tines of the lift truck or the like is common in the Grocery Manufacturers Association (GMA) type of pallets. To provide four-way entry, some runners include notches which are open to the bottom face of the runner to provide entry of the tines on the lift truck into the runner for lifting the pallet as is shown in the present inventor""s prior application, Ser. No. 09/182,263 which matured into U.S. Pat. No. 6,095,061.
However, if the tines of the forklift or lift truck are not properly positioned in the notches to lift and transport the load or the load is unbalanced, the load could potentially tilt and fall off of the tines. As such, many manufacturers and/or operators often add stringers along the bottom open face of the notches in an effort to stabilize such loads supported on the tines and inhibit the load from tipping or falling off. Nevertheless, stringers of this type typically cannot be added to wood runners or are often ineffective, particularly for heavily loads that could be easily damaged, torn or dislodged during use thereby becoming ineffective for their intended purpose.
Thus, there is an increasing need for pallets which are economically and ecologically feasible. However, an acceptable pallet must possess the strength to support their intended loads particularly on a rack or conveyor and must be sufficiently durable to withstand repeated use including being lifted with a lift truck or the like while loaded. Further, desirably the pallet must resist deterioration by the elements of the weather. Moreover, an acceptable pallet must be competitively priced in the marketplace.
Therefore, it is apparent that there is a need in the industry for a pallet and/or runner which satisfies these and other criteria and overcomes the associated disadvantages and shortcomings of known pallet and runner designs.
The improved runner and pallet constructed therewith overcomes the above-described disadvantages of wood pallets and pallets or runners made from alternative materials known in the shipping, packaging and container industries. Advantageously, the pallet and runner design according to this invention is economically feasible while being lightweight and providing significant strength and increased load bearing capability and resistance to compression or crushing so that the pallet/runner can support a load on a rack or conveyor. Importantly, the pallet/runner design of this invention, while providing these significant advantages over know pallet/runner designs, is also entirely processible in a paperboard recycling system or the like for convenient, economical and ecological disposal.
Specifically, a pallet according to a presently preferred form of this invention includes at least two spaced generally parallel runners and each of the runners is constructed of a number of layers of double wall or double face corrugated paperboard glued together in face to face orientation with the flutes of the corrugations being generally aligned in a generally vertical direction. Each of the runners also includes at least one generally vertically oriented reinforcing insert positioned interiorly of the runner between adjacent layers of the corrugated paperboard.
Furthermore, in still other presently preferred embodiments, the runner may include a band with a number of nylon, polyester or other material strands situated between the adjacent layers of the corrugated paperboard or incorporated into the various layers of the corrugated paperboard during manufacturing. The band may be used in addition to or as an alternative to the reinforcing inserts. The band is primarily added to the runner to minimize catastrophic rupture, tearing or failure of the paperboard runner as it approaches its maximum load limit. For example, runners which include such a band would begin to sag as they approach they load limit while runners without such a band would fail without warning or notice or opportunity for replacement of the pallet or runner.
Each of the runners preferably includes at least two spaced notches or portals with the respective notches or portals being aligned with one another so that the tines of a lift truck or the like can be inserted therein in a direction generally perpendicular to the runners for lifting the pallet and the load supported thereon. The runners are spaced and generally parallel so that the tines of the lift truck can alternatively be inserted generally parallel to the runners for lifting the pallet and the load and thereby providing what is known in the industry as four-way entry into the runner. The notches in the runner are generally open to the bottom surface of the runner; whereas, in an alternative embodiment, the portals are formed as throughholes in the runners and generally perpendicular to the adjacent layers of paperboard. The portals provide a safety feature in that the pallet is inhibited from tipping off of a forklift while picking up pallets with the tines inserted in the portals. Moreover, the portal configuration provides increased strength relative to the open bottom notches disclosed in U.S. Pat. No. 6,095,061.
A pallet constructed with the above-described runners may also include a generally planar upper deck sheet joined to an upper surface of each of the runners and a generally planar lower deck sheet generally parallel to the upper deck sheet and joined to a lower surface of the runners. Alternatively, the upper deck sheet may include a plurality of sidewalls each projecting generally upwardly from a perimeter thereof to define a tray atop the runners to contain the load on the pallet.
The runners may be used separately from the pallet construction. As such, a deposit of adhesive in a presently preferred form is applied to the upper surface of the runner to secure the runner, at least temporarily, to the lower surface of a load to thereby enable the load to be lifted by a lift truck and stored on a rack or the like.
A significant advantage of the pallet/runner design according to this invention is that all of the components of the pallet/runner are entirely processible in a paperboard recycling system while still providing strength and stability for use under a load on a rack or conveyor. In prior pallet designs, wood components used either exclusively or in combination with paperboard or other materials prevented the pallet/runner from being processed in a paperboard recycling system. When a shipment of goods or the like is received by a customer, the paperboard boxes or cartons containing those goods are commonly disposed of in a paperboard recycling station. However, the associated pallet/runner was shipped to a landfill or the wood components were manually separated from the other materials. Advantageously, the pallet/runner design of this invention can be deposited into the recycling system along with the cartons or boxes to provide an economical and ecological disposal of the pallet/runner without the labor intensive task of separating the various materials.
Commonly, wood pallets must be quarantined upon arriving at international shipping destinations; whereas, primarily paperboard pallets such as the present invention are not required to be quarantined to avoid the spread of regional diseases, harmful insects or the like.
Various commercial consumers have specifically identified a need for a pallet which can be: 1) placed in a corrugated waste bailer or recycling station at each store so that the components thereof can be processed and sold for recycling along with the used paperboard boxes and other containers commonly processed therein; 2) strong enough to be stored in racks in the same manner as wooden pallets; and 3) has the same four-way entry feature as a wooden pallet. Importantly, these objectives must be obtained in an economical manner to offer a commercially viable alternative to wood pallets. The present invention satisfies these and other requirements.
Wood pallets are typically competitively priced at about $7.50 per pallet; whereas, estimates for the pallet of this invention are very economical at about $6.00 to $6.50 per pallet. Moreover, the pallet/runner according to this invention is very lightweight, on the order of about 17 to 18 pounds per pallet thereby providing for easy maneuvering and handling thereof.
While still being lightweight, the pallet/runner, due in large part to the reinforcing insert and/or band and the flute orientation of the corrugated paperboard, provides significant strength and load bearing capability while resisting compression or crushing. While the chipboard, fiberboard, linerboard, Kraft and paperboard are materials of the reinforcing insert that are common to the shipping, packaging and container industry, particleboard and hardboard provide significant strength to the runner and are materials not typically known in those industries. Particleboard and hardboard are commonly used in the building or construction industry. Furthermore, the hardboard is the most preferred reinforcing insert material because it is primarily a wood fiber based component, it can be die cut, laminated, sawed or otherwise shaped as is required, although such techniques are not commonly employed in the building industry for hardboard. Additionally, hardboard and the other materials for the reinforcing insert are each resistant to the absorption of water and moisture or the like and, therefore, the strength of the runner/pallet does not significantly degrade when exposed to these conditions unlike known primarily paperboard pallet or runner designs.
The corrugated paperboard of the runner offers compression resistance and alignment stability such that the runner does not easily twist, bend, buckle or turn when loaded with a non-vertically aligned load. However, the corrugated paperboard offers little or no beam strength to the runner design. As such, known corrugated paperboard runners deflect dramatically and/or fail when placed on the beams of a rack under load. The reinforcing insert of hardboard or the like provides beam strength and resistance to compression for the pallet/runner but offers very little alignment stability to the pallet/runner. Therefore, this invention advantageously combines these two components into a pallet/runner design which offers alignment stability, beam strength and compression resistance.
As a result, the pallet/runner of this invention overcomes the significant disadvantages of wood pallets while offering an ecological and economical alternative that provides considerable strength and weight bearing capability so that loads can be easily placed on a rack or the like without compression or crushing of the pallet/runner. The entire pallet/runner can be processed in a paperboard recycling station for ecological and convenient disposal thereof and offers a safer alternative to known pallet/runner designs by avoiding catastrophic failures without warning and minimizing the opportunity for the runner supported load to tip off of the tines of a lift truck.